The background description provided here is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
During manufacturing of semiconductor devices, etch processes and deposition processes may be performed within a processing chamber. Ionized gas, or plasma, can be introduced into the plasma chamber to etch (or remove) material from a substrate such as a semiconductor wafer, and to sputter or deposit material onto the substrate. Creating plasma for use in manufacturing or fabrication processes typically begins by introducing process gases into the processing chamber. The substrate is disposed in the processing chamber on a substrate support such as an electrostatic chuck or a pedestal.
The processing chamber may include transformer coupled plasma (TCP) reactor coils. A radio frequency (RF) signal, generated by a power source, is supplied to the TCP reactor coils. A dielectric window, constructed of a material such as ceramic, is incorporated into an upper surface of the processing chamber. The dielectric window allows the RF signal to be transmitted from the TCP reactor coils into the interior of the processing chamber. The RF signal excites gas molecules within the processing chamber to generate inductively-coupled plasma.
The TCP reactor coils are driven by a transformer coupled capacitive tuning (TCCT) match network. The TCCT match network receives the RF signal supplied by the power source and enables tuning of power provided to the TCP reactor coils. The TCCT match network may include variable capacitors. Each of the variable capacitors includes a stationary electrode and a movable electrode. A capacitance of the corresponding capacitor is directly related to position of the movable electrode relative to the stationary electrode. The movable electrodes can be connected to a leadscrew, which can be driven by a rotary motor.
Power supplied to each of the TCP reactor coils is based on positions of the movable electrodes of the capacitors. A ratio of power delivered to the TCP coils is also based on the positions of the movable electrodes of the capacitors. One or more power ratios provided during etching can be different than one or more power ratios provided during deposition.